1. Field of the Invention
This invention relates to finger and hand exercisers for medical and non-medical applications.
2. Description of the Prior Art
U.S. Pat. No. 5,147,256 (Silagy) discloses a combination individual finger and entire hand exerciser. As disclosed in the Silagy '256 patent, the exerciser includes three cooperating body members, mainly an upper body member 12, a centrally disposed body member 14 and a lower body member 16. Body member 12 is provided to promote individual finger exercising and includes four adjacent, individually independently slidable finger grips 12a, 12b, 12c and 12d. The bottom body member 16 is provided to promote entire hand exercising.
Each of the finger grips 12a-12d is maintained in an initial clearance position from the centrally disposed body member 14 by a helical spring 30 which is disposed in an encircling relation about a pin 34 which is slidable in the middle body member 14. Exposed caps 18a-18d of the upper body member 12 are respectively provided on finger grips 12a-12d. A user may contact the caps 18a-18d with his fingers and press down on finger grips 12a-12d against the resistance of springs 30 to exercise his fingers.
It is noted that the tension in the exercising springs 30 forming part of the finger grips 12a-12d is not adjustable by the user, and may provide too great or too little resistance for the user's individual fingers when the user is performing exercises with the finger and hand exerciser disclosed in the Silagy '256 patent.
Another finger and hand exerciser is disclosed in U.S. Pat. No. 5,431,611 (Silagy). The Silagy '611 patent discloses an exerciser where the finger plunger components that are pressed by the user are allegedly adjustable in size to accommodate the hand width and finger length dimensions of the user.
The Silagy '611 patent discloses that the finger and hand exercising device includes four resistance spring, plunger-type, finger-actuated members 12a-12d, each of which is attached to a base 14. Each finger-actuated member includes an externally threaded, height-adjusting member 30 which is threadingly engaged with a housing 24 and in which is received an exercise spring 36. Slidably disposed in relation to height-adjusting member 30 is a tube 46 for containing spring 36. A removable cap 60 for engagement with a user's finger is removably threaded onto tube 46 to hold the exercising spring in place.
The user may raise or lower the height of the finger-actuated members 12a-12d to adjust for variations in the user's finger lengths by turning threaded member 30 in housing 24 of each of the plungers 12a-12d. 
It should be noted from the Silagy '611 patent that the tension of the exercising springs 36 is not individually adjustable and remains the same even as the height of the plungers 12a-12d is adjusted. In fact, the Silagy '611 patent teaches that the cap 60 must be removed from tube 46 to replace and insert an exercise spring 36 of an appropriate construction material and helical turns or configuration to vary the exercise effort in using the device.